Water heater with side wall air supply and venting means



A. B. MCCORQUODALE 3,320,935

May 23, 19 7 WATER HEATER WITH SIDE WALL AIR SUPPLY AND VENTTNG MEANS Filed March 29, 1965 INVENTOR. ALAN B. MCCORQUODALE w.e.mW,%

ATTOR/Vfl United States Patent 3,320,935 WATER HEATER WITH SIDE WALL AIR SUPPLY AND VENTING MEANS Alan B. McCorquodale, 907 7th St., Orange, Tex. 77630 Filed Mar. 29, 1965, Ser. No. 443,440 1 Claim. (Cl. 122-494) This invention relates toa water heater assembly which is particularly adapted for installation in automotive trailers or other relatively small spaces such as bathrooms. More particularly the invention is directed to a water heater assembly which includes means for supplying air through a side wall of the trailer or bathroom as the sole source of air for the burner and also for venting the combustion gases through the same side wall.

Automobile trailers of the type utilized as mobile homes often are provided with gas water heaters which can be operated on liquefied propane or butane or on natural gas provided at so-called trailer camps. The heater usually is installed in a cabinet beneath a sink installed within the trailer adjacent one of its walls, and it generally is desirable to vent the heater through the side wall. However, conventional vents heretofore provided for this purpose have not been entirely satisfactory, since in windy weather drafts can blow through them into the heater cabinet and cause the pilot light conventionally provided with the heater to become extinguished. Also it is not unusual that rain can enter the heater cabinet through the venting means.

In my patent United States No. 2,974,650 a water heater with side wall venting means adapted for use with automotive trailers was disclosed. The heater tank was provided with a jacket, a burner beneath the tank and projecting through an opening in the bottom of the jacket, means for venting combustion gases from the side of the jacket through a vent in the side Wall of the trailer and annular means surrounding the flue gas vent for admitting fresh air. The fresh air first entered a cabinet provided within the trailer and surrounding the jacketed heater and then flowed to the burner. The flue gas venting means included a riser having an opening at its bottom for diverting blasts of wind from outside the vent into the cabinet so as to prevent the burner pilot light from blowing out. In this arrangement most of the air for combustion was supplied from the side wall air inlet. However, no provision was made for entirely sealing off the burner from the interior of the trailer and hence a minor amount of air could also pass to the burner from openings in the cabinet such as door openings or cracks, windows, louvers or the like. While this assembly performed as desired under most conditions, it was not completely satisfactory when Weather conditions caused inordinately strong winds. While the open ended draft diverter arrangement generally prevented the pilot light from becoming extinguished, the backdraft through it could result in occasional passage of flue gases through openings in the cabinet into the living quarters space within the trailer.

The present invention provides a Water heater assembly which is an improvement over that described in my aforesaid patent. The present assembly likewise includes side wall inlet and venting means, :but in addition it embodies means which provide a completely enclosed passageway from the air inlet to the burner and thence to the side wall vent. The present arrangement is such that all air that enters m-ust flow directly to the burner while the flue gas produced can pass only to the side wall vent and thence to the atmosphere. This obviates any possibility of escape of flue gas into the trailer 3,326,935 Patented May 23, 1967 or room in which the heater is installed while insuring that the burner and pilot light flames will not be extinguished due to air blasts.

The invention is described more specifically in conjunction with the accompanying drawing wherein:

FIG. 1 is an elevational view, partly in section, of the water heater and its associated side wall inlet and venting means;

FIG. 2 is an elevational view of the panel which serves, inter alia, to cover the opening in the trailer wall through which the heater is installed within the trailer cabinet; and

FIG. 3 is a cross-sectional view on the line 3-3 of FIG. 1.

Referring to the drawing, numeral 10 represents the side wall of a trailer and the space 11 represents the interior of a cabinet within the trailer. An opening 12 is provided in the trailer wall at the cabinet for installation of the heater therein.

The heater assembly comprises a hot Water container such as a vertical cylindrical tank 13 surrounded by and spaced from a jacket indicated generally at 14 and comprising a cylindrical side wall 15, top and bottom members 16 and 17 and suitable insulation 18 at the sides and top. The bottom member 17 has an opening 20 in which a conventional burner 21 provided with a pilot light 22 is positioned. The burner and pilot light are connected through lines 23 and 24, respectively, to a fuel control valve 25 provided with a thermostat 26 in conventional manner. A skirt 19 extends downwardly from the bottom of the heater jacket to support member 27 and forms therewith a vestibule 28 which is substantially sealed off from the cabinet space 11. Skirt 19 has an opening at 29 through which burner arm 30 extends from vestibule 28 to connect with fuel line 23. Control valve 25 is connected to a supply line (not shown) for a suitable fuel which preferably is hydrocarbon gas such as butane, propane, natural gas or manufactured gas. Alternatively a liquid fuel such as kerosene or fuel oil can he used in cases where the installation is adapted for use with liquid fuels.

The wall opening 12 through which the heater is installed in the trailer is provided with a cover panel 31 which is attached to trailer wall 10 by means of bolts 32. Panel 31 has a rectangular slot at 33 which is normally closed by a smaller panel 34 secured to panel 31 as illustrated by means of bolt 35. The small panel 34, which serves as a window for observation of and access to pilot light 22 and burner 21, is provided with several small holes 36 adjacent the bottom. The purpose of holes 36 is to permit escape of gas to the outside in the event of any gas leakage from connections to the pilot light 22 or burner 21. The jacket 14 for the heater may contain a slot 37 between small panel 34 and pilot light 22 to provide access to the pilot light, although this is not essential and opening 29 alternatively can be used for access.

Panel 31 and jacket 14 each contain apertures, shown respectively at 39 and 38, which are in horizontal axial alignment with each other and jacket aperture 38 has a vent conduit 40 projecting therethrough. An air supply and venting assembly illustrated at 41 is constructed for mounting as an integral unit at panel aperture 39 and vent conduit 40. This assembly comprises a sleeve 42 which fits snugly over the outer part of vent conduit 40, a flanged conduit member 43 positioned around sleeve 42 and fitting snugly into panel aperture 39, and a pair of spaced apart transverse baffles 44 and 45 for diverting the outward flow of flue gas substantially radially as it emerges from the sleeve 42. The assembly is held together by threaded rods 46 which project through transverse baffies 44 and 45 and through a circular end member 47, all being fastened firmly together by means of screw caps 48. The inner end of conduit member 43 preferably is flared inwardly to aid in preventing rain water from entering with the fresh air.

The heater jacket 14 and panels 31 and 34 are arranged to cooperate with other baflle elements to form a confined fresh air flow channel 52 between the panel opening 39 and the burner 21. These other baffle elements comprise vertical bafiles 49 and 50 extending from the jacket 14 to panel 31 and a baffle 51 closing the top of the channel.

When the burner is operating, flows of fresh air and combustion gases take place in the manner indicated by arrows in FIG. 1. Fresh air enters the apparatus between transverse baflle 44 and flanged conduit member 43, passes down channel 52 and then passes to burner 21 through vestibule 28 and opening and through slot 37 in the jacket. A small amount of air enters through holes 36 in door panel 34 but this is insignificant. Thus the entire air supply comes directly from outside of the trailer through the wall and essentially none can enter from the cabinet. The combustion gases, after passing around the tank 13, flow through vent conduit 40 and as they emerge from the outer end of sleeve 42 are diverted substantially radial-1y to the atmosphere. As shown in FIG. 1 transverse baffles 44 and 45 preferably are slightly conical so that the path of the diverted flue gas before it reaches the outside is mainly but not precisely lateral. The hot flue gas in passing through the venting assembly gives up some of its heat through members 42 and 44 to the incoming fresh air, while the latter prevents panel 31 from becoming too hot.

The above-described arrangement insures proper functioning of the heater even under atmospheric conditions where high winds are prevalent. Tests have shown that the pilot light will not be snuffed out in winds of forty miles per hour velocity. The present invention permits this result to be obtained while at the same time insuring against any possibility of exhaust gas flow from the heater through the cabinet in which it is installed and into the living quarters of the trailer. The fact that proper flow of gases within the heater assembly occurs even under highly adverse wind conditions results from the arrangement whereby a substantially enclosed or confined path is provided from the air inlet to the flue gas outlet. This in combination with the inlet and venting assembly structure insures proper flow. When winds blow against the panel 31 a somewhat higher pressure is developed at the air inlet adjacent bafile 44 than at the flue gas outlet. Thus there is a differential pressure which dictates proper flow of gas through the apparatus. When still higher winds are encountered, higher pressures at the air inlet and flue gas outlet may develop but the differential pressure will be substantially the same. Hence the disclosed structure automatically compensates for higher winds and prevents inordinate drafts that otherwise might extinguish the pilot light. Further, the difference in densities of the column of cold fresh air in flow channel 52 and of the hot gases around the tank 13 and in sleeve 42 insure the proper circulation through the confined flow path within the assembly.

While the invention has been specifically described above for an assembly having a vertically cylindrical tank as the hot water container, the invention is equally applicable to coil type heaters. Thus in place of the tank 13 a conventional coil can be used and the same benefits 4 as described above will be obtained from having the enclosed or confined flow path extending from the air inlet to the flue gas outlet.

The invention is also applicable for heating air instead of water. Hence the invention can be utilized in the form of an air heater for the purpose of heating the inside of a trailer or a room in a house such as a bathroom. For this purpose the invention embodies the construction as described above which provides an enclosed or confined flow path extending from the air inlet through the heating chamber to the flue gas outlet. However, instead of a hot water container which is a tank or coil, the heating chamber contains other means providing a heat transfer surface through which heat is conducted from the hot flue gases to fresh air which is heated and then circulates within the trailer or room. For example the heat transfer means can comprise a tube bundle having finned tubes through which the heat is transferred from the hot flue gases to the air. Other means providing suitable heat transfer surfaces will be apparent to those skilled in the art.

I claim:

A water heater assembly adapted for positioning in a cabinet in an automotive trailer through an opening in a wall of the trailer which comprises:

(a) a container having a convex bottom and adapted to hold a body of water,

(b) a jacket around the container spaced therefrom and having a side opening adjacent the top of the tank and a bottom opening beneath the tank, said container and jacket providing therebetween an annular space for flow of flue gas from said convex bottom to said side opening,

(c) a burner positioned beneath the tank at said bottom opening,

((1) a panel adapted for closing the opening in the trailer wall, said panel having a removable door for access to the burner and an opening in lateral alignment with said side opening,

(e) means forming an enclosed fresh air flow channel between said panel opening and the burner, whereby the sole supply of air for the burner is through the panel,

(f) flue gas venting means comprising an outlet conduit extending laterally from said side opening through and beyond said panel opening and spaced apart transverse slightly conical baflles parallel to each other beyond the panel opening for diverting the flow of flue gas substantially radially from the conduit but slightly outwardly from said panel, and

(g) flanged conduit means adapted to fit within the panel opening and flatly against the panel and forming with the innermost of said conical bafiles and with said outlet conduit an inlet path for fresh air to said flow channel.

References Cited by the Examiner UNITED STATES PATENTS 2,788,943 4/1957 Fauser 12685 2,974,650 3/1961 McCorquodale 122-494 3,028,843 4/1962 Carlson et al. 12685 3,056,400 10/1962 Hammersley et al. l26--85 3,091,223 5/1963 Vitale 126-85 FREDERICK L. MATTESON, J 11., Primary Examiner,

ROBERT A. DUA, Assistant Examiner. 

